What is CID 984 & How to Solve It?

What is CID 984:

cid 984 indicates an issue with the intake air heater relay circuit. the ecm detects that the relay is not functioning correctly, affecting cold starts and initial combustion quality.

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Why This Happens:

• faulty intake air heater relay.
  
• corroded or loose connectors.
  
• open circuit or short to voltage.
  
• failed heater element.
  
• ecm control signal fault.
  
  

How to Fix It:

1. inspect the relay and its wiring for damage.
   
2. test resistance of the intake air heater.
   
3. verify relay operation during key-on cycles.
   
4. repair or replace faulty connectors or relays.
   
5. confirm system response using diagnostic tools.
   
   

How to Avoid It Before It Happens:

• test relays during preventive maintenance.
  
• protect connectors from moisture exposure.
  
• perform cold start checks seasonally.
  
• clue’s equipment maintenance services monitor cold start systems to prevent downtime in harsh conditions.